Related Experiment Videos
Production of left ventricular cavitary obliteration in normal man
Insights
Left ventricular cavitary obliteration, previously seen only in hypertrophic states, can be induced in normal subjects. This finding demonstrates that altered loading conditions can cause cavitary obliteration in healthy left ventricles.
Area of Science:
- Cardiology
- Cardiovascular Physiology
Background:
- Left ventricular cavitary obliteration is a phenomenon typically observed in hypertrophic conditions.
- Its occurrence in individuals without cardiac hypertrophy is not well-established.
Purpose of the Study:
- To investigate the potential induction of left ventricular cavitary obliteration in subjects with normal left ventricles.
- To explore the effects of altered loading conditions on left ventricular cavity dynamics.
Main Methods:
- Cardiac catheterization was performed on 16 patients without coronary artery disease or hypertrophic obstructive cardiomyopathy.
- Left ventriculography was conducted at rest and during the Valsalva maneuver with amyl nitrite administration.
- Patients were categorized into two groups based on resting left ventriculogram: normal (Group A) and hyperkinetic (Group B) left ventricles.
Main Results:
- Amyl nitrite and Valsalva maneuver significantly reduced left ventricular volumes and increased ejection fraction in Group A.
- Eight Group A patients developed total and two developed partial cavitary obliteration post-provocation.
- All six Group B patients exhibited total cavitary obliteration after provocation, with some showing partial/complete emptying at rest.
- Transvalvular pressure gradients were observed in both groups post-provocation.
Conclusions:
- Left ventricular cavitary obliteration can be experimentally induced in normal left ventricles.
- Manipulation of loading conditions is a key factor in provoking cavitary obliteration.
- These findings suggest that cavitary obliteration is not exclusive to hypertrophic states and can occur in healthy hearts under specific physiological stress.
Abstract:
To determine whether left ventricular cavitary obliteration (a finding previously described only in hypertrophic states) can be induced in normal subjects, 16 patients without coronary artery disease or clinical evidence of hypertrophic obstructive cardiomyopathy were studied during cardiac catheterization. Resting left ventricular and aortic pressures and left ventriculography were repeated during the strain phase of Valsalva maneuver after administration of amyl nitrite. Cavitary obliteration during normal sinus rhythm was defined as disappearance of the sinus portion of the left ventricle during systole, and graded as absent, partial or total. Patients were placed into two groups on the basis of qualitative analysis of the resting left ventriculogram: the 10 patients in group A had normal left ventriculograms and the six patients in group B had hyperkinetic left ventricles. During the left ventriculogram done with amyl nitrite and Valsalva, left ventricular volumes in both decreased dramatically, from 69 ml/m2 to 43 ml/m2 (p less than 0.001) and ejection fraction increased from 70% to 82% in group A (p less than 0.01). None of the patients in group A had evidence of cavitary obliteration at rest, but eight developed total and two developed partial cavitary obliteration with the second ventriculogram. Three patients in group B had partial or complete cavitary emptying at rest and all developed total cavitary obliteration with provocation. Pressure gradients between left ventricle and aorta were produced in two group A patients and three group B patients. Thus, cavitary obliteration can be produced in normal left ventricles by manipulation of loading conditions.